Is it necessary to strictly diagnose fibromyalgia syndrome in patients with chronic widespread pain?

The applicability of the American College of Rheumatology (ACR) 1990 and 2010 criteria for the diagnosis of fibromyalgia syndrome (FMS) was determined in 284 patients with chronic widespread pain (CWP) including those with regional and systemic painful disorders. On the basis of initial evaluation, patients were classified into three groups. Group 1, those without any comorbid disease (N = 105), group 2, those having regional non-inflammatory painful disorders (N = 104), and group 3, those with a diagnosis of an inflammatory rheumatic disease (N = 75).